Quantum mechanical molecular dynamics simulations of polaron formation in methylammonium lead iodide perovskite
Quantum mechanical molecular dynamics simulations of polaron formation in methylammonium lead iodide perovskite
复制标题
甲铵碘化铅钙钛矿中极化子形成的量子力学分子动力学模拟
DOI：
10.1039/c9cp04739e
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发表时间：
2020
影响因子：
3.3
通讯作者：
and Hiromi Nakai
中科院分区：
文献类型：
--
作者：
Hiroki Uratani;Chien-Pin Chou;and Hiromi Nakai
通过量子力学分子动力学模拟，研究了具有代表性的钙钛矿太阳能电池吸收剂甲基碘化铅钙钛矿（MAPbI3）中极化子形成的原子和动力学机制。模拟是在几个纳米的空间尺度上进行的，可以描述电荷的局部化和相关的结构变形，使用分而治之的密度功能紧密结合方法，可以对包含数千个原子的系统进行量子化学处理。我们发现MAPbI3的结构部分，即无机骨架（PbI3−）和MA阳离子都涉及与极化子形成相关的结构变形。在极化子形成过程中，热结构波动引起电荷局域化，载流子的弛豫引起进一步的结构变形。最后，从能量学的角度分析了PbI3−和MA这两个结构部分的重要性。
We investigated the atomistic and dynamical mechanism of polaron formation in methylammonium lead iodide perovskite (MAPbI3), which is a representative perovskite solar cell absorber, through the quantum mechanical molecular dynamics simulations. The simulations were conducted on the spatial scale of several nanometres, which can describe charge localization and the associated structural deformation, using the divide-and-conquer-type density-functional tight-binding method, which enables a quantum chemical treatment of systems comprising thousands of atoms. We found that both the structural parts of MAPbI3, namely, the inorganic framework (PbI3−) and the MA cations, involve the structural deformation associated with polaron formation. We elucidated that in the process of polaron formation, charge localization is invoked by thermal structural fluctuation, and a further structural deformation is caused by the relaxation of the charge carrier. Finally, importance of the two structural parts, PbI3− and MA, was examined from the energetical viewpoint.